Mystery Coolant Loss 1.8T
 

I am losing about 1-200ml of coolant a day on only a short trip. Some have suggested it the IMG, but I can't see any evidence of that (although of course it may be), doesn't seem to be much loss around the t piece although there is some pink - a little on the back of the radiator. Anyone have any other places to look, any checks?

There are several places a typical 1.8 loses coolant and are regularly discussed on the forum. Hose connections are pretty obvious candidates, as well as the infamous IMG. Other places are the plastic T-piece as you mention as well as the water pump.

If the cooling fan doesn't work correctly, overheating may cause coolant to be ejected under excess pressure from the header tank cap. Have you run the standard Demist Test on the fan? Have you checked the actual running temperature using the Trip Screen Diagnostics? If neither of these mean anything, I'm sure links will be provided.

Perhaps less discussed than the obvious sites is the head gasket coolant channel seals. To examine this possibility, check the oil level frequently to ensure it's not going up as you lose coolant. OAT coolant mixing with engine oil doesn't necessarily create 'mayo' on the dipstick. The two will combine when churned in the engine to prduce a dark viscous emulsion that simply looks like old engine oil. This can happen through spontaneous failure of the elastomer beading on the OEM head gasket.

This type of failure is much more common than realised and tends to be classed as the usual 'HGF', but it's not. I've recently fixed mine following a sudden dumping of the coolant into the sump. The head gasket didn't 'fail' in the classic sense. There was no prior overheat, no loss of compression or power. The coolant simply leaked past the head seals in a matter of minutes. The underlying cause here is the poor quality of the rubber beading and its bonding to the metal gasket. It imply lifts off as seen here. Some say OAT antifreeze is the culprit. Maybe it is, and maybe not.

https://www.mediafire.com/convkey/0c...0ex7neoe6g.jpg

I'm not saying this is your issue, but it's something to be very aware of. The 1.8 engine needs a lot of TLC and even given that, things like this happen quite often. Good luck.

TC

Thanks for the info Tcut.

I have just ran the diognostic on the temp and it is showing 91/92 on idle with a bit of revs after a short school run about 10 minutes previously.

Only other thing I can note is that there seems to be quite a bit of steam coming from the exhaust whilst revving on the drive. It doe snot seem to be smoke at all as I got right by it and cannot smell anything.

Just ran the fan test, put the econ button on and pressed demist, fan kicks in.

If the exhaust is clearly very steamy, it means coolant is getting into the cylinders. That's typically via a leaky IMG. You might get more signs by looking at No1 and 4 spark plugs. IMG leakage usually affects these by producing a 'washed' appearance and the ceramic insulator may be stained pink (if you use OAT antifreeze). Also remove the oil filler cap when the engine's running. See if there's any obvious steam coming out of there.


TC

On my wife's K series I've used a multi-layer Reinz gasket.

So far so good. It's quite thick, has roughly 5 layers to it ( it was a while since I fitted it ) and has a Teflon coating.

Thanks, do you have a link to it? can only find them in kits

Check out the information on DMGRS website re which gasket to choose. It is not possible to choose the correct gasket until after the head has been removed and examination of the head and liner heights are checked. Lots of K series have been scrapped due to "multiple" head gasket failures. The internet is awash with information about head gasket failures on K series. My head gasket was replaced (on my 1.8) with an (upgraded) elastomer gasket and has run perfectly well ever since.

Yep, plenty of info about. I wouldn't fit anything other than an elastomer. Never had been much wrong with them and they aren't any less "strong" than an MLS. I have one on my current zt and fitted one to my track 25 when I rebuilt it 5 years ago and that's has some serious abuse since, no issues as far as reliabilitys concerned.

As said earlier in the thread, whip the spark plugs out. You can't rule anything out until you've done some investigation.

Bit lost here now. Are we talking about IMG or Head gasket?

OK! Here we go:-
Inlet manifold gasket failures usually give a misfire at start up as coolant seeps internally into the combustion chambers via the inlet. External leaks will be seen leaving coolant traces on the outside of the engine. Easiest and cheapest option, so worth a try to eliminate it.


Head gasket failures will usually give rise to excess pressure in the coolant accompanied by mixing of oil and coolant which looks like mayonaisse.